Effects of Experimental Trypanosoma Congolense Infection on Sperm Morphology in Yankasa Rams

The objective of the study was to determine the effect of T. congolense on the sperm morphology of Yankasa rams (YKR). Nine YKR aged 24-30 months-old were assigned into two groups of 6 infected and 3 uninfected control and were monitored for 7 weeks. The infected group of YKR was each inoculated with 1 × 106 T. congolense through the jugular vein, while the control group remained uninfected. The entire infected group developed trypanosomosis post infection (pi) characterized by sperm morphological abnormalities in the semen. There were significant (P<0.001) increases in the mean percentage of acrosomal, head, middle piece and tail abnormalities. Proximal and distal droplets as well detached heads were also significantly (P<0.001) increased post infection (pi). Acrosomal abnormalities, distal droplet and tail abnormalities increased from week 1 pi till the end of the study, while head abnormalities and detached heads increased from week 2 pi. Middle piece abnormalities and proximal droplets increased from week 3 and 4 pi till the end of the study respectively. The high incidence of morphological defects caused by T. congolense is capable of causing infertility from the first week pi thereby making the rams unfit for breeding at the end of the study.